The 25-year-old from Banchory holed a 40-foot eagle putt at the last to seal success in style in the £60,000 Ciputra Golfpreneur Tournament in Jakarta.
In closing with a flawless 64 – his card also contained three birdies in each half – for a 17-under-par total of 271, Byrne won by three shots from Indonesia’s William Sjaichudin (65) and American Brett Munson (70).
It has mainly been a frustrating three years for the one-time highest-ranked Scottish amateur since joining the paid ranks after helping Great Britain & Ireland win the 2011 Walker Cup at Royal Aberdeen.
He recorded back-to-back victories in the Northern Open and also won on the ADT in Malaysia early last year. But his attempts so far to secure a European Tour card have ended in disappointment, and he then lost his Asian Tour card following a poor 2013 campaign.
“This is by far my most satisfying win,” said Byrne, who, prior to his victory, had only made three cuts in eight appearances on the ADT this season but has leaped to eighth on the order of merit after picking up a cheque for £10,500.
With seven events to come – the first starts in Manila on Wednesday – he aims to finish inside the top five on the money list at the end of the season to regain an Asian Tour card for 2015.
“I didn’t play well on the Asian Tour to keep my card and I’ve been disappointed that I haven’t been closer to the top five on the ADT Order of Merit,” added the 2010 Amateur Championship runner-up at Muirfield.
“Hopefully this win will change things. I’ve been playing so badly and, at some point, you think on what you have been doing with your career.
“I’ve been working on the right things and change doesn’t happen immediately. I knew what I was doing in practice and I was confident the scores would improve.”
Byrne is scheduled to launch his European Tour card bid in the first stage event at The Roxburghe, near Kelso, next month, when hopefuls are also set to include David Law and Craig Lawrie. “That was a special win today as it was one that I really needed. Roll on Manila!” added Byrne later on Twitter.